1. Field of the Invention
The invention relates to a method and apparatus for balancing the out-of balance forces in centrifuges or combined washing machines-spin driers with a monitoring provision, which interrupts the regular acceleration of the drum to the final rotary spinning speed if out-of-balance forces are to large.
2. Brief Description of the Background of the Invention Including Prior Art
In order to avoid destruction and damage to centrifuges, the use of monitoring provisions to switch off the drive is known. A known improvement of such machines does not switch off the drive completely, but lowers the rotation speed to such an extent that the clothes in a drum with a horizontal rotation axis release from the drum wall shortly before reaching the highest point of the drum wall and fall along a free flight path into the lower part of the drum. If the rotation speed is increased slowly, then the free flight path disappears and all the clothes cling again like a ring to the drum. By way of the free flight path the clothes have been redistributed and in most cases out-of-balance forces have been balanced by this step such that the drum can then be accelerated to the final rotary spinning speed. It has been found that despite the free flight path the clothes sometimes still retain out-of-balance distributions, since a clothes piece can wind up to a ball-shaped tangle during the washing procedure. Such a tangle remains in the lower part of the drum upon beginning of clinging to the drum and it rotates there like a ball such that it never reaches the upper part of the drum and never passes into the free flight path.